At least two-thirds of registered voters failed to vote in every neighborhood in the city.

The highest turnout — 33% — was in the upper-income coastal enclave of Pacific Palisades. The lowest, only 7%, was in Watts.

The analysis found the highest turnout was in city council districts in the Westside and West Valley. District 11 in the Westside saw 25.3% turnout in March. District 12 in the northwest Valley saw 24.6%. (See the full interactive map.)

Many of the communities with the lowest turnout are poor and also have large numbers of residents ineligible to vote, such as unnaturalized immigrants, further diminishing the clout of those neighborhoods at City Hall, experts say.

"You create this cycle where politicians tend to ignore council districts with lower turnout," said Matt Baretto, a political scientist at the University of Washington in Seattle. "When they get into office, regardless of who they are, they just provide less services, so voters feel like 'why should I vote?' "

Tawana Percy, a cashier who lives in the Gonzaque Village complex in Watts, is one of many who don't see the point of choosing between L.A. mayoral runoff candidates Eric Garcetti and Wendy Greuel.

"Everything will still be the same in my life," Percy, 32, said as she pushed her baby's stroller down the sidewalk of a Watts strip mall on her way to buy diapers.

The plunge in voter turnout is part of a long, nationwide trend, broken periodically as it was when Barack Obama was elected president. Low turnout in the city's March primary also reflected a failure by Garcetti, Greuel and their rivals to generate much public enthusiasm.

Edmund Edelman was on the City Council when voter turnout in Los Angeles elections peaked 44 years ago. He sees the sharp drop-off as a sign of "cynicism about government and a sense that elections don't matter."

"People have lost faith in elected officials," he said. "They see so many politicians putting ambition and personal need over the public good."